Chronic conditions and
co-morbidity among residents
of British Columbia
Anne-Marie Broemeling
Diane Watson
Charlyn Black
February 2005
“Chronic conditions and co-morbidity among residents of British Columbia” was produced by:
Centre for Health Services and Policy Research
The University of British Columbia
429-2194 Health Sciences Mall
Vancouver, BC Canada V6T 1Z3
Tel: (604) 822-1949
Fax: (604) 822-5690
Email: [email protected]
You can download this publication from our website at www.chspr.ubc.ca.
This publication is protected by copyright. It may be distributed for educational and noncommercial use, provided the Centre for Health Services and Policy Research is credited.
Table of Contents
About CHSPR ...................................................................................................ii
Acknowledgements ........................................................................................iii
1. Introduction .................................................................................................1
1.1 Why study chronic conditions and co-morbidity?......................................................................... 1
2. Methods .......................................................................................................4
2.1 Study population ......................................................................................................................... 4
2.2 Data source..
4
2.3 Classifying the study population .................................................................................................. 4
2.4 Classifying chronic conditions ...................................................................................................... 5
2.5 Co-morbidity in the study population .......................................................................................... 6
2.6 Utilization ....
6
3. Results .........................................................................................................7
3.1 Chronic conditions among British Columbia residents, 2000/01 .................................................. 7
3.2 High impact and/or high prevalence chronic conditions ............................................................ 10
3.3 Co-occurrence of chronic conditions .......................................................................................... 14
3.4 Recognizing co-morbidity among individuals with chronic conditions....................................... 14
3.5 Expected resource use by level of co-morbidity ......................................................................... 17
3.6 Chronic conditions, co-morbidity and use of health care services .............................................. 19
3.7 Chronic conditions, co-morbidity and high users of health care services ................................... 22
4. Discussion ..................................................................................................23
5. Conclusions ................................................................................................26
6. Limitations .................................................................................................27
Appendix A: Distribution of study population by patient category ................... 28
Appendix B: Standardized utilization rates of health care services ...............30
Appendix C: Data methods ............................................................................35
References .....................................................................................................36
Chronic conditions and co-morbidity among residents of British Columbia
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About CHSPR
The Centre for Health Services and Policy Research (CHSPR) is an independent research centre based
at the University of British Columbia. CHSPR’s mission is to stimulate scientiﬁc enquiry into issues
of health in population groups, and ways in which health services can best be organized, funded and
delivered. Our researchers carry out a diverse program of applied health services and population health
research under this agenda.
CHSPR aims to contribute to the improvement of population health by ensuring our research is relevant
to contemporary health policy concerns and by working closely with decision makers to actively translate
research ﬁndings into policy options. Our researchers are active participants in many policy-making
forums and provide advice and assistance to both government and non-government organizations in
British Columbia (BC), Canada and abroad.
CHSPR receives core funding from the BC Ministry of Health Services to support research with a direct
role in informing policy decision-making and evaluating health care reform, and to enable the ongoing
development of the BC Linked Health Database. Our researchers are also funded by competitive external
grants from provincial, national and international funding agencies.
Much of CHSPR’s research is made possible through the BC Linked Health Database, a valuable resource
of data relating to the encounters of BC residents with various health care and other systems in the
province. These data are used in an anonymized form for applied health services and population health
research deemed to be in the public interest.
CHSPR has developed strict policies and procedures to protect the conﬁdentiality and security of these
data holdings and fully complies with all legislative acts governing the protection and use of sensitive
information. CHSPR has over 30 years of experience in handling data from the BC Ministry of Health
and other professional bodies, and acts as the access point for researchers wishing to use these data for
research in the public interest.
For more information about CHSPR, please visit www.chspr.ubc.ca.
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Centre for Health Services and Policy Research
Acknowledgements
This project was conducted with funding from an ongoing contribution agreement with the BC Ministry
of Health Services.
It builds on a collaborative research project with the Vancouver Coastal Health Authority (VCH). The
original project with VCH developed a proﬁle of chronic health conditions, co-morbidity, and health care
utilization among VCH residents. We are very grateful to Mark Chase, who originally identiﬁed the need
for information on chronic health conditions to inform health planning and service delivery, and who
encouraged the collaborative research between VCH and CHSPR.
Funding for the VCH research project was provided in the form of a postdoctoral fellowship (AM
Broemeling), with ﬁnancial support provided both by VCH and the Canadian Health Services Research
Foundation. We are grateful for this support and the foundation the VCH work has provided for this
provincial project.
The results and conclusions are those of the authors and no ofﬁcial endorsement by the funders is
intended or should be inferred.
Special thanks also go to a number of staff at CHSPR, including Sherin Rahim-Jamal, Bo Green, Peter
Schaub and Heidi Matkovich for their assistance with this project.
Chronic conditions and co-morbidity among residents of British Columbia
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1. Introduction
Chronic health conditions have been identiﬁed
as a key challenge for health care during the
twenty-ﬁrst century.1 Chronic conditions affect a
signiﬁcant proportion of the population, not only
in Canada, but around the world.2,3,4 The majority
of health care services are used by individuals
with chronic conditions5 and the cost of treating
chronic conditions is signiﬁcant.6,7 In Canada,
67 per cent of total direct health care costs and
60 per cent of indirect costs in terms of lost
productivity and foregone income are attributed
to chronic diseases.8
Chronic health conditions are those expected
to persist or to recur, usually beyond one year,
and range from persistent skin disorders such as
psoriasis, to recurrent psychosocial conditions
such as chronic depression, to complex, high
impact conditions such as chronic renal failure,
congestive heart failure, and cerebrovascular
disease. Chronic conditions are signiﬁcantly
associated with increasing age and gender,9
and lower socioeconomic status,10 and include
both diseases such as diabetes, and health
states involving disability, such as post-stroke
impairment. As the population ages, the needs
of people with chronic conditions are expected
to place increasing demands on health care
providers and health care delivery systems.
The impact of chronic conditions and the need
to introduce chronic condition prevention
has been identiﬁed as a priority for the newly
created Public Health Agency of Canada.11 The
Romanow Commission on the Future of Health
Care in Canada also identiﬁed the needs of those
with chronic conditions as an area for future
attention,12 and the recent national consultation
on health services and policy issues for 2004–2007,
Listening for Direction II, identiﬁed chronic
disease management as an important issue for
sustainability in Canada.13
The purpose of this report is to proﬁle patterns
of chronic health conditions among British
Columbia residents, the presence of multiple
conditions (co-morbidity) among those with
chronic conditions, and the impact of chronic
conditions and co-morbidity on utilization of
health care services.
1.1 Why study chronic conditions and
co-morbidity?
More than 50 per cent of Canadian adults—
and 81 per cent of community-dwelling seniors—
report having a chronic health condition.3
Individuals with chronic conditions account for
a signiﬁcant proportion of health services use: in
the US, 76 per cent of direct medical costs are for
those with chronic conditions.5 A recent study of
high users of medical services in British Columbia
found that high users were more likely to have
multiple conditions, including a combination of
chronic conditions and psychosocial conditions,
and high users more frequently had speciﬁc
chronic conditions such as congestive heart failure,
cerebrovascular disease, cancer, and cardiac
arrhythmia.14 Similar ﬁndings were reported
among American Medicare recipients, where onequarter of beneﬁciaries had four or more types of
chronic conditions and were responsible for twothirds of Medicare expenditures.15
At the same time, evidence suggests that the
quality of care provided to individuals with
chronic conditions is less than optimal. Care
for chronic conditions has been described as
“a poorly connected string of episodes
determined by patient problems. Physicians,
hospitals, and other health care organizations
operate as silos, often providing care without
the beneﬁt of complete information about the
patient’s condition, medical history, services
provided in other settings, or medications
Chronic conditions and co-morbidity among residents of British Columbia
|1
prescribed by other clinicians.”1 Research suggests
that continuity of care contributes to increased
use of preventive services, reduced utilization of
emergency and acute care services, and improved
patient outcomes and satisfaction.16
Receipt of recommended, evidence-based,
preventive, treatment, and follow-up care
(technical effectiveness) contributes to improved
patient outcomes.17 Yet care for individuals
with chronic health conditions often focuses on
acute exacerbations of persistent or recurrent
conditions rather than regular monitoring and
preventive care. Many individuals with chronic
conditions fail to receive recommended services,
preventive monitoring, education, and care for
associated functional and psychosocial needs. In
British Columbia in 2002/03, only 39 per cent of
individuals received recommended hemoglobin
testing, 43 per cent received recommended eye
examinations, 34 per cent received recommended
microalbumin testing, and 78 per cent received the
recommended lipid testing for preventive diabetes
management.18 Similar results have been reported
in other jurisdictions.17,19
In response to concerns about continuity,
coordination, and technical effectiveness of
health services for those with chronic health
conditions, chronic disease management
programs have been implemented in a number
of jurisdictions, including British Columbia.
These programs focus on management of speciﬁc
chronic conditions with the objective of reducing
utilization and treatment costs, and/or improving
patient outcomes. Chronic disease management
programs most commonly target asthma, diabetes,
depression, hypertension, congestive heart failure,
and arthritis.20 These initiatives typically include
identiﬁcation of individuals with a speciﬁc
chronic condition (development of a chronic
disease registry) and introduction of one or more
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measures to manage the condition. In many
cases (e.g. congestive heart failure, hypertension),
disease management focuses on pharmacotherapy
regimens. Chronic disease management programs
may also include patient education (selfmanagement training), physician decision support
(evidence-based guidelines or protocols, training
for recommended care, shared care), and clinical
information systems with recommended care
and follow-up reminders to promote continuity
of care. The “chronic care model” emphasizes
the combination of measures in an integrated
approach to chronic disease management.21
Chronic disease programs often focus on a single
condition. However, many people have multiple
chronic conditions, which tend to “cluster” in
individuals.22,23,24 In the US, more than 40 per
cent of individuals with chronic conditions—
and almost 70 per cent of those aged 65 and
over—had more than one chronic condition.5 Yet
little is known about the distribution of people
with single or multiple chronic health conditions
in Canada. This type of information is critical
to planning and organizing health services as
the care for individuals with multiple chronic
conditions is complex and often involves patients
receiving treatment from several providers in
various settings.
Research from the US and Europe indicates that
individuals with multiple chronic conditions
use more health care services23,25 and are more
likely to experience ambulatory care sensitive
or preventable hospitalizations,15,26 activity or
functional limitation or disability,27 decreased
well-being and quality of life,28 and are more
likely to report poor health status.29 As well,
individuals with multiple conditions are less likely
to receive recommended treatment for other
medical conditions,30,31 and are more likely to
use multiple pharmaceuticals and complex drug
regimens with attendant risk of drug interactions.
Individuals with multiple chronic conditions may
also be less likely to receive appropriate primary
health care and are more likely to experience poor
coordination of care.15
This report was designed to address
the following questions:
• What is the experience of British
Columbians with chronic health
conditions and co-morbidity?
• How do individuals with chronic health
conditions and co-morbidity use health
care services compared to individuals
with no chronic conditions or individuals
with chronic conditions and no or low
co-morbidity?
• How do individuals with chronic health
conditions and co-morbidity overlap with
high users of health care services? Do
chronic disease programs target those
with highest use of services?
The report proﬁles the treatment prevalence
of chronic health conditions and co-morbidity
among residents of British Columbia. The impact
of chronic conditions and co-morbidity on both
expected and actual utilization of health care
services is described. Information is provided to
identify the overlap between those with chronic
conditions and co-morbidity and high users of
health care services. This report is intended to
enhance understanding of chronic care needs and
to inform the planning for, and management of,
chronic care for residents of British Columbia.
Chronic conditions and co-morbidity among residents of British Columbia
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2. Methods
2.1 Study population
The study population included adult residents
(18+ years of age) of British Columbia registered
with the British Columbia Medical Services
Plan (MSP). Results are reported for adults
who were registered with MSP for 275+ days
as well as individuals who died during 2000/01.
Sensitivity analyses were performed using varying
registration periods (185+ days, 275+ days, 335+
days, 365 days, with and without deaths during
the year) to assess the impact of enrollment period
on results: diagnoses are an endogenous variable
and complete identiﬁcation of speciﬁc conditions
could be affected by the length of time individuals
were enrolled and receiving services. Detailed
analyses were completed for study populations
for each of the following years: 1997/98, 1998/99,
1999/00, and 2000/01. Similar results were
found for each study year, indicating that the
morbidity measurement strategy is reliable and the
conclusions were stable over a 4-year period.
2.2 Data source
Data were extracted from the British Columbia
Linked Health Database (BCLHD) at the
Centre for Health Services and Policy Research.
Data accessed through the BCLHD included
client registry, Hospital Discharge Abstract,
Medical Services Plan (MSP), Continuing
Care Information Management System, and
PharmaCare Plan A & B ﬁles. Census-derived
information for neighborhood income provided
an ecological measure of socioeconomic status.
Probabilistic and deterministic linkage methods
developed by CHSPR were used to link data from
individual administrative ﬁles. These methods
result in over 95 per cent linkage rates.32 Data
were anonymized to ensure conﬁdentiality and
protection of privacy.
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Centre for Health Services and Policy Research
Medical services provided by salaried and
sessional physicians and service organizations
funded through the Alternative Payments
Program (APP) were not included since
individual-level data are not available from this
source. As a result, we likely understate treatment
prevalence rates for chronic conditions, overall
morbidity, and utilization rates for individuals
who rely predominantly on these APPfunded services. During the time frame under
investigation, psychiatric, oncology, pediatric,
primary care, geriatric, and emergency services
were most frequently provided under alternative
payments. APP service expenditures have been
increasing during the past 20 years.33
2.3 Classifying the study population
Chronic conditions were identiﬁed using ICD9
diagnoses from MSP claims data and from the
Hospital Discharge Abstract data ﬁle. Diagnosis
codes were grouped into more than 50 speciﬁc
chronic conditions with an expected duration
of more than one year using the Expanded
Diagnosis Clusters (EDCs) methodology.34
This methodology groups diagnosis codes into
commonly occurring ambulatory conditions and
is useful for minimizing the impact of differential
coding of common conditions. ICD9 diagnosis
codes were also grouped using Adjusted Clinical
Groups (ACGs) to summarize the types of
conditions and overall morbidity experienced by
individuals during a one-year time period. ACG
assignments reﬂect the range and severity of
conditions, as well as age and gender.35
Individuals in the study population were classiﬁed
into the following mutually exclusive categories to
reﬂect both use of health care services and types
of diagnosed conditions:
Chronic conditions: individuals with chronic
conditions were identiﬁed using the EDCs
grouping methodology for chronic conditions
with an expected duration of greater than one
year. Individuals with chronic conditions were
further categorized as those with:
conﬁrmed chronic conditions: those individuals
with at least two medical or one hospital
diagnoses for at least one chronic condition
during the two-year period;* or
possible chronic conditions: those individuals
with a single chronic condition diagnosis
during the two-year period; that is, they may
have a chronic condition but this was not
conﬁrmed with a second medical diagnosis.
Acute conditions: individuals with medical
and/or hospital service use but no identiﬁed
chronic condition(s) were categorized as having
acute conditions.
2.4 Classifying chronic conditions
In order to focus the analysis from chronic
conditions generally to a relevant subset of
conditions, chronic conditions were further
categorized by prevalence and impact using
data for 1997/98.
Prevalence was estimated using treatment
prevalence rates in the study population.
Treatment prevalence rates identify individuals
who were treated for speciﬁc chronic conditions.
Individuals who have undiagnosed conditions or
who did not seek treatment are not identiﬁed. It
is important to note that treatment prevalence
rates for speciﬁc chronic conditions in this study
were based on different diagnosis groupings as
well as different data sources than those used by
the British Columbia Ministry of Health Services
to develop provincial chronic disease registries.
For example, Ministry registries incorporate
additional prescribing data from the PharmaNet
database to identify chronic conditions, a data
source that was not available for this study. It is
anticipated that treatment prevalence rates in this
analysis understate chronic condition prevalence
and will be lower than prevalence rates reported in
the British Columbia chronic disease registries.
Impact was based on expected short-term resource
use and outcomes as estimated using Adjusted
Clinical Groups (ACGs) and hospital/medical cost
weights from previous research.36 ACGs measure
the range and severity of conditions experienced
by individuals during a one-year period and
provide a combined measure of expected impact
that is predictive of utilization.34,35
Combining prevalence and impact: Chronic
conditions were classiﬁed according to both
prevalence and impact since both prevalence
and the expected impact of a chronic condition
contribute to the overall impact of that condition
on health services utilization in the population.
I M PAC T
P R E VA L E N C E
Non-users: non-users of health care services were
identiﬁed as those individuals with no medical or
hospital service use during the study year (ACG 5200).
LOW
HIGH
HIGH
High prevalence &
low impact
High prevalence &
high impact
LOW
Low prevalence &
low impact
Low prevalence &
high impact
* The two diagnosis requirement, along with the decision to exclude laboratory and diagnostic imaging service diagnoses,
was used to increase sensitivity and speciﬁcity of case identiﬁcations and to reduce potential rule-out diagnoses.
Chronic conditions and co-morbidity among residents of British Columbia
|5
For this study, speciﬁc chronic conditions that
were high impact and/or high prevalence chronic
conditions (HI/HP CCs) were identiﬁed in order to
recognize the importance of both prevalence and
impact for planning chronic care services.
2.5 Co-morbidity in the study population
Co-morbidity measures estimate the co-occurrence
of additional conditions among individuals
with an index condition. The presence of comorbidity was identiﬁed using ACGs (e.g.
ACG 4330: individuals with 4 to 5 ADGs, age
18–44, 2+ major ADGs) and reﬂects types
of conditions rather than speciﬁc chronic
conditions. Individuals were identiﬁed as having:
no co-morbidity (single condition), low comorbidity (2 to 3 types of conditions), medium
co-morbidity (4 to 5 types of conditions), high
co-morbidity (6 to 9 types of conditions), and
very high co-morbidity (10+ condition types).
2.6 Utilization
Two measures of utilization were used in
this study: expected resource use, and actual
utilization.
Expected resource use estimates resource use
by sub-groups of the population relative to the
population average and was based on ACG cost
estimates. The average cost for individuals in each
group was compared to the population average
using an index. This expected resource use index
enables comparisons of combined medical and
hospital service use by sub-groups, such as those
with chronic conditions compared to those with
acute conditions.
Actual utilization rates were also calculated and
recognize the use of home care, home support,
and pharmaceutical services in addition to
hospital and medical care. Actual utilization
rates were calculated and stratiﬁed by type
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of user—acute, chronic, those with HI/HP
CCs—and by co-morbidity level. Utilization
rates were calculated for medical services (GP,
specialist, total visits, and expenditures); hospital
services (acute/rehab, alternate level of care, total
inpatient days); direct home care services (home
nursing care, home rehab services, total direct
care visits); home support (homemaker hours and
expenditures); and PharmaCare (Plan A and Plan
B) use by seniors. Crude and age/sex-standardized
utilization rates were calculated.
Additional data methods are described in
Appendix C.
3. Results
3.1 Chronic conditions among British
Columbia residents, 2000/01
Figure 2 describes the distribution of residents
into non-user, acute, chronic, and possible
chronic condition categories by health authority
(HA) for 2000/01.
In 2000/01, 36 per cent of adult residents of
British Columbia had at least one conﬁrmed
chronic condition. A further 18 per cent had at
least one possible chronic condition, based on a
single diagnosis for at least one chronic disease.
Thirty-three per cent of residents had acute
conditions only. The remaining 13 per cent of
residents were non-users of services.
The proportion of residents with chronic
conditions ranged from 31 per cent in the
Northern Health Authority to 39 per cent for
Vancouver Island Health Authority, reﬂecting,
in part, the relatively younger population in the
North and older age distribution among residents
of Vancouver Island. Age/sex standardized
rates by health authority indicate fairly similar
distribution by patient category (Appendix A).
The higher proportion of non-users and lower
proportion of residents with chronic conditions
among residents of some health authorities may
also reﬂect use of APP services in rural and
remote areas and missing Alberta utilization data
from which diagnoses are identiﬁed.
As illustrated in Table 1, the proportion of seniors
with chronic conditions was signiﬁcantly higher:
68 per cent had at least one conﬁrmed chronic
condition and a further 15 per cent had possible
chronic conditions. Eleven per cent had only acute
conditions and less than 6 per cent were non-users
of services during 2000/01.
Chronic condition prevalence increased with age
and a higher proportion of women than men had
diagnosed chronic conditions (Figure 1). The
proportion of residents with chronic conditions
was higher among the residents of the lowest
income neighborhoods (38.5 per cent) than
among residents of higher income neighborhoods
(34.1 and 34.0 per cent).
Table 1: Distribution of chronic conditions among adult study population, 2000/01
Adults 18+ years
(n=2,933,305)
Seniors 65+ years
(n=545,059)
% distribution
Non-users
13.3
5.6
Acute conditions
32.6
11.4
Possible chronic condition(s)
18.5
14.6
Conﬁrmed chronic condition(s)
35.7
68.4
TOTAL
100.0
100.0
Chronic conditions and co-morbidity among residents of British Columbia
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Centre for Health Services and Policy Research
0
10 %
20 %
30 %
40 %
50 %
60 %
70 %
80 %
90 %
100 %
18-34
years
16.9
47.8
18.1
17.2
35-49
years
16.0
37.8
19.9
26.4
50-64
years
11.5
24.3
20.1
44.1
65-74
years
6.4
13.2
15.8
64.6
By age group
75+
years
4.7
9.4
13.3
72.6
(low)
Q1
13.2
30.6
17.7
38.5
Q3
12.8
33.0
18.6
35.6
Q4
13.3
33.8
18.8
34.1
Income quintile
Q2
12.9
32.1
18.4
36.6
By income quintile
(high)
Q5
13.2
33.8
19.1
34.0
18.3
33.5
16.6
31.6
females
8.7
31.8
20.1
39.4
By sex
males
Figure 1: Distribution of chronic conditions by age group, neighborhood income and sex
Percent of residents
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Non users
Acute Conditions
Chronic Conditions (possible)
Chronic Conditions (confirmed)
Patient categories
Figure 2: Distribution of chronic conditions by health authority
Among adults (18+) in BC...
Patient categories by health authority
Fr aser HA
12.1 %
32.6 %
18.9 %
36.4 %
Patient categories
among adults (age 18+)
Non-users
Acute Conditions
Vancouver Coastal HA
14.8 %
33.3 %
18.5 %
33.4 %
Chronic Conditions (possible)
Chronic Conditions (confirmed)
Source: BC Linked Health Database (CHSPR)
Vancouver Island HA
11.2%
31.6 %
18.2 %
39.0 %
Interior HA
13.0 %
32.2 %
18.0 %
36.8 %
Northern HA
18.1 %
33.2 %
18.1 %
30.6 %
Province-wide
13.3 %
32.6 %
18.5 %
35.7 %
Chronic conditions and co-morbidity among residents of British Columbia
|9
3.2 High impact and/or high prevalence
chronic conditions
Both prevalence and impact are important when
assessing the overall impact of speciﬁc chronic
conditions. Both prevalence and impact are also
important when planning to meet needs for health care
services and management of chronic health conditions.
Treatment prevalence rates for selected
chronic conditions varied signiﬁcantly in the
study population, with recurrent depression
and hypertension the most prevalent chronic
conditions among adults in British Columbia.
Aplastic anaemia and chromosomal anomalies
were among the conditions with lowest treatment
prevalence rates.
The expected impact of different types of chronic
conditions also varied signiﬁcantly. Conditions
such as allergic rhinitis had a relatively lower
expected impact, while congestive heart failure
and cerebrovascular disease were higher impact
chronic conditions.
Treatment prevalence rates and impact
information were combined to categorize chronic
conditions by prevalence and impact, with
mid-points used to group conditions into high
impact/lower impact and high prevalence/lower
prevalence (Figure 3).
Chronic obstructive pulmonary disease/chronic
bronchitis/emphysema (COPD), cardiac
arrhythmia, and ischemic heart disease were high
impact as well as high prevalence conditions.
Hypertension, diabetes, and degenerative joint
disease were high prevalence but lower impact,
while conditions such as endometriosis were lower
prevalence and lower impact. HIV/AIDs, chronic
renal failure, and a small number of other chronic
conditions were high impact but lower prevalence.
Many high prevalence conditions were lower
impact (e.g. depression, hypertension, asthma,
diabetes) whereas the highest impact conditions,
including cerebrovascular disease, congestive
heart failure, and chronic renal failure, were less
prevalent in the population.
In order to identify a subset of chronic conditions
for detailed analysis, chronic conditions that
were high impact and/or high prevalence were
identiﬁed using combined prevalence and impact
data. Conditions to the upper right of the curved
line in Figure 4 represent the mix of high impact
and/or high prevalence conditions. These speciﬁc
high impact/high prevalence chronic conditions
(HI/HP CCs) were: recurrent depression,*
hypertension, asthma, diabetes, degenerative
joint disease, ischemic heart disease (IHD),
cancer,† cardiac arrhythmia, chronic obstructive
pulmonary/chronic bronchitis/emphysema
(COPD), congestive heart failure (CHF), and
cerebrovascular disease.
A number of these conditions (diabetes, hypertension,
congestive heart failure, asthma, chronic lung disease,
depression, arthritis) were also identiﬁed as priorities for
chronic disease management in British Columbia,37 and
two conditions (diabetes and congestive heart failure)
have been the focus of chronic disease collaboratives.
As illustrated in Figure 5, a signiﬁcant majority of
those with conﬁrmed chronic conditions had at least
one HI/HP CC in 2000/01. The proportion of the
population with chronic conditions and one or more
HI/HP CCs varied only slightly across the province.
* Depression was deﬁned as two or more medical diagnoses or one or more hospitalizations with depression in
order to focus on persistent or recurrent depression rather than a short-term episode.
† Cancers were deﬁned as malignant neoplasms and excluded skin cancers and benign tumours.
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Chronic conditions and co-morbidity among residents of British Columbia
| 11
Prevalence
0
5
10
15
20
25
30
35
90
0
ADD
Chronic Cystic
Dis Breast
Obesity
2
Congenital
anom: limbs
MS
CF
4
Personality
disorders
Chromosomal
Devt
dis
IBD
Seizure
Malignant
neoplasm
of skin
Prostatic
hypertrophy
Autoimmune /
conn. tissue
Glaucoma
Endometriosis
Psoriasis
Deafness / Hearing loss
Allergic Rhinitis
Dis Lymphoid Metab.
Thyroid Dis
Asthma
Diabetes
Hypertension
Degenerative
joint disease
Depression
Peripheral vascular
disease
Cardiac valve dis
Chronic liver dis
Dementia /
delerium
8
Chronic renal
failure
Chronic skin ulcer
Cerebrovascular disease
Congestive
heart failure
Cardiomyopathy
Blindness
Impact
6
HIV /AIDS
HAnem
Generalized
atherosclerosis
Kyphoscoliosis
MD
CHD
Parkinson’s
Osteoperosis
MIDPOINT
Schizophrenia/
affective psychosis
Diverticular
dis. of colon
COPD
Cardiac Arrhythmia
Cancers
Ischemic heart disease
Figure 3: Treatment prevalence and expected impact of chronic conditions
MIDPOINT
10
Aplastic anemia
Centre for Health Services and Policy Research
0
5
10
15
20
25
30
35
90
0
ADD
Chronic Cystic
Dis Breast
Obesity
2
Congenital
anom: limbs
MS
CF
4
Personality
disorders
Chromosomal
Devt
dis
IBD
Seizure
Malignant
neoplasm
of skin
Prostatic
hypertrophy
Autoimmune /
conn. tissue
Glaucoma
Endometriosis
Psoriasis
Deafness / Hearing loss
Allergic Rhinitis
Dis Lymphoid Metab.
Thyroid Dis
Asthma
Diabetes
Hypertension
Degenerative
joint disease
Depression
Peripheral vascular
disease
Cardiac valve dis
Chronic liver dis
Dementia /
delerium
8
Chronic renal
failure
Chronic skin ulcer
Cerebrovascular disease
Congestive
heart failure
Cardiomyopathy
Blindness
Impact
6
HIV /AIDS
HAnem
Generalized
atherosclerosis
Kyphoscoliosis
MD
CHD
Parkinson’s
Osteoperosis
Schizophrenia/
affective psychosis
Diverticular
dis. of colon
COPD
Cardiac Arrhythmia
Cancers
Ischemic heart disease
Figure 4: High impact and/or high prevalence chronic conditions
Prevalence
12 |
10
Aplastic anemia
Figure 5: High impact and/or high prevalence chronic conditions by health authority,
Among adults with at least
one chronic condition...
Among adults (18+) in BC...
Patient categories by health authority
Percentage with
HI/HP CC
Fr aser HA
12.1 %
32.6 %
18.9 %
36.4 %
78.8 %
of that 36.4 %
Vancouver Coastal HA
14.8 %
33.3 %
18.5 %
33.4 %
77.2 %
of that 33.4 %
Vancouver Island HA
11.2%
31.6 %
18.2 %
39.0 %
80.5 %
of that 39.0 %
Interior HA
13.0 %
32.2 %
18.0 %
36.8 %
82.4 %
of that 36.8 %
Northern HA
18.1 %
33.2 %
18.1 %
30.6 %
79.0 %
of that 30.6 %
Province-wide
13.3 %
32.6 %
18.5 %
79.4 %
35.7 %
of that 35.7 %
Patient categories
among adults (age 18+)
Non-users
Acute Conditions
Chronic Conditions (possible)
Chronic Conditions (confirmed)
Those with any
confirmed chronic
condition
Source: BC Linked Health Database (CHSPR)
Chronic conditions and co-morbidity among residents of British Columbia
| 13
3.3 Co-occurrence of chronic conditions
Many individuals had more than one chronic
health condition, and common co-occurring
conditions were observed. Co-occurrence of
speciﬁc chronic conditions was evident for each
HI/HP CC. Thirty-one per cent of individuals
with diabetes also had hypertension and 11 per
cent of individuals with diabetes had depression
(Table 2). Ten per cent of individuals with diabetes
and hypertension also had depression, accounting
for 3 per cent of all diabetes cases.
The co-occurrence of speciﬁc chronic conditions
was signiﬁcantly higher than expected, using
regression analyses and adjusting for age and sex,
supporting the view that chronic conditions tend
to cluster in some individuals.
3.4 Recognizing co-morbidity among
individuals with chronic conditions
In light of the ﬁnding that some individuals
had multiple co-occurring chronic conditions,
it is important to understand the extent of comorbidity (presence of conditions in addition to
an index chronic condition) among individuals.
Co-morbidity was estimated as the range of
condition types experienced by individuals
during one year.
Figure 6 describes the distribution of comorbidity in the study population and by patient
group. For the total study population, 11 per cent
had high co-morbidity (6 to 9 condition types)
and 2 per cent had very high co-morbidity
(10+ condition types).
Table 2: Common co-occurring HI/HP chronic conditions among individuals with diabetes
Proportion of adults with diabetes
(n=117,274) AND:
(%)
Hypertension
31
Proportion of adults
with diabetes and
hypertension (n=35,987)
AND:
(%)
Depression
11
10
IHD
10
13
17
Degenerative joint
6
8
11
12
Cardiac arrhythmia
4
6
7
16
Cancer
4
4
6
7
CHF
4
5
6
21
Cerebrovascular
3
4
6
11
Asthma
3
3
5
5
COPD
2
2
3
5
14 |
Centre for Health Services and Policy Research
Proportion of adults with
diabetes, hypertension,
depression (n=3,746)
AND:
(%)
Proportion of adults with
diabetes, hypertension,
depression, IHD (n=637)
AND:
(%)
Among adults with only acute conditions, comorbidity was relatively low: only 2.5 per cent
had high or very high co-morbidity. On the other
hand, for those with conﬁrmed chronic conditions,
30 per cent of adults with chronic conditions had
high or very high co-morbidity. Similar results were
found for those with one or more high impact/high
prevalence chronic conditions.
Across health authorities, the proportion of
residents with HI/HP CCs and very high comorbidity (10+ condition types) ranged from 6
to 7 per cent. A further 23 to 27 per cent of HI/
HP CC residents had high co-morbidity (6 to 9
condition types). Lower proportions of residents
with high and very high co-morbidity in the
Northern Health Authority may be due to missing
Alberta hospital utilization and diagnosis data.
Figure 7 indicates the proportion of the
population with HI/HP CCs by co-morbidity level
across British Columbia.
Figure 6: Co-morbidity by patient category
Co-morbidity level
none
low
medium
high
very high
HI/HP CC
9.0 %
27.9 %
30.7 %
25.9 %
6.7 %
Chronic conditions (confirmed)
9.8 %
30.0 %
30.2 %
24.1 %
5.8 %
Acute conditions
40.3 %
49.7 %
7.6 %
2.4 %
Total 18+ study population
13.3 %
20.1 %
non-user
2.4 %
pregnancy
33.8 %
17.1 %
0.1 %
11.0 %
2.3 %
Chronic conditions and co-morbidity among residents of British Columbia
| 15
32.6 %
33.3 %
13.3 %
18.5 %
18.1 %
18.0 %
18.2 %
18.5 %
18.9 %
35.7 %
30.6 %
36.8 %
39.0 %
33.4 %
36.4 %
Chronic Conditions (confirmed)
Chronic Conditions (possible)
Acute Conditions
Non-users
Patient categories
among adults (age 18+)
32.6 %
33.2 %
32.2 %
31.6 %
Province-wide
18.1 %
Northern HA
13.0 %
Interior HA
11.2%
Vancouver Island HA
14.8 %
Vancouver Coastal HA
12.1 %
Fr aser HA
of that 35.7 %
of that 30.6 %
of that 36.8 %
of that 39.0 %
of that 33.4 %
of that 36.4 %
Those with any
confirmed chronic
condition
79.4 %
79.0 %
82.4 %
80.5 %
77.2 %
78.8 %
Percentage with
HI/HP CC
8
10
8
7
8
7
28
31
29
28
28
31
30
31
31
31
31
26
23
26
27
26
27
Co-morbidity
7
6
6
7
7
7
Source: BC Linked Health Database (CHSPR)
of that 79.4 %
of that 79.0 %
of that 82.4 %
of that 80.5 %
of that 77.2 %
of that 78.8 %
28
Percentage at
co-morbidity level
none
Patient categories by Health Authority
Among adults with at least
one HI/HP CC
low
Among adults with at least
one chronic condition...
medium
Among adults (18+) in BC...
Figure 7: Co-morbidity among those with high impact and/or high prevalence chronic conditions
high
Centre for Health Services and Policy Research
very high
16 |
3.5 Expected resource use by level
of co-morbidity
the population average, and those with medium
co-morbidity were expected to use slightly more
than the population average (1.3). However,
individuals with chronic condition(s) and high
co-morbidity were expected to use 3.5 times the
resources of the population average, and those
with chronic condition(s) and very high comorbidity were expected to use almost 10 times
the population average.
Expected resource use was estimated for those
with acute or chronic conditions. Compared with
the adult population average (1.0), adults with
acute conditions were expected to use, on average,
0.4 times the resources of the adult population
(Table 3). On the other hand, those with chronic
conditions were expected to use twice the
resources of the population average.
There were also important differences in comorbidity among individuals with speciﬁc chronic
conditions. Nine per cent of adults with diabetes
had no co-morbidity while a majority had low
or medium co-morbidity. Twenty-ﬁve per cent
of individuals with diabetes were in the high comorbidity group and 7 per cent were in the very
high co-morbidity category (Figure 8).
Looking further at the impact of co-morbidity,
those with a conﬁrmed chronic condition and no
co-morbidity had an expected resource use 0.2
times that of the population average. Those with
a chronic condition and low co-morbidity were
expected to use about 0.5 times the resources of
Table 3: Distribution of co-morbidity (CM) and expected resource use index
DISTRIBUTION
BY CO-MORBIDITY
(CM)
LEVEL
EXPECTED RESOURCE USE
BY CO-MORBIDITY (CM)
(%)
INDEX
LEVEL
Non
user
No
Low
Med
High
V High
No
Low
Med
High
V High
Total
13.3
20.1
33.8
17.1
11.0
2.3
0.1
0.4
1.2
3.3
9.5
1.0
Acute only
40.3
49.7
7.6
2.4
0.1
0.1
0.4
1.0
2.5
7.8
0.4
Conﬁrmed
chronic
9.8
30.0
30.2
24.1
5.8
0.2
0.5
1.3
3.5
9.8
2.0
HI/HP CC
9.0
27.9
30.7
25.9
6.7
0.2
0.5
1.3
3.6
9.9
2.2
Total adults*
*The remaining 2.4 per cent are patients with pregnancy ACGs and are excluded due to the signiﬁcant
short-term resource impact associated with pregnancy (Reid RJ, et al. Conspicuous consumption:
Characterizing high users of physician services in one Canadian province. J Health Serv Res Policy 2003;
8(4):215–224).
Chronic conditions and co-morbidity among residents of British Columbia
| 17
Figure 8: Expected resource use by adults with diabetes
Expected Resource use index
Co-morbidity level
10.0
5.0
3.9
2.4
1.0
Co-morbidity
Percent of all adults
with diabetes
1.2
Total study pop.
0.1
0.6
none
(9%)
low
(29%)
The overall expected resource use for diabetes was
2.4, indicating that individuals with diabetes were
expected to use almost two and a half times the
resources of the population average. However,
the 9 per cent of adults with diabetes and no comorbidity were expected to use only 0.1 times
the resources of the population average, while
adults with diabetes and low co-morbidity were
expected to use about 0.6 times the resources of
the population average. Adults with diabetes and
medium co-morbidity had expected resource use
slightly higher than the population as a whole:
1.2 vs. 1.0. However, adults with diabetes and high
co-morbidity were expected to use 4 times the
resources of the population average, and adults
with diabetes and very high co-morbidity were
expected to use almost 12 times the resources of
the population average.
18 |
11.5
none
low
medium
high
very high
Centre for Health Services and Policy Research
medium
(30%)
high
(25%)
very high
(7%)
all diabetes
(100%)
Co-morbidity was more prevalent among adults
with congestive heart failure (CHF) than among
adults with diabetes (Figure 9). A smaller
proportion of CHF patients had no reported comorbidity (3 per cent) and a majority of CHF
patients had high (43 per cent) or very high (21
per cent) co-morbidity. Those with high comorbidity were expected to use 6 times as many
resources as the population average, and those
with very high co-morbidity were expected to
use 14 times the resources. As a result of the
relatively higher level of co-morbidity, adults with
congestive heart failure were expected to use 6.1
times the resources of the population average.
For each HI/HP CC, some individuals had no
or low co-morbidity and relatively low expected
resource use while others had high or very high
co-morbidity and high expected resource use.
Figure 9: Expected resource use by adults with congestive heart failure
Expected Resource use index
15.0
Co-morbidity level
none
low
medium
high
very high
10.0
6.1
6.0
5.0
2.4
1.0
Co-morbidity
Percent of all adults
with CHF
14.2
Total study pop.
0.4
none
(3%)
0.6
low
(12%)
The proportion of individuals with very high
co-morbidity and expected resource use varied
by condition. Only 6 per cent of those with
hypertension were in the very high co-morbidity
level. Similarly, 7 per cent of those with diabetes,
8 per cent of those with depression, and 11 per
cent of those with asthma were in the very high
co-morbidity and high resource use group. For
COPD, cardiac arrhythmia, ischemic heart disease,
and cancer, approximately 14 to 17 per cent were in
the very high co-morbidity group. Cerebrovascular
disease and congestive heart failure had the highest
proportions in the very high co-morbidity group
with 19 and 21 per cent respectively. Distribution
of co-morbidity was important to the relative
expected resource use over and above the presence
of a speciﬁc chronic condition.
medium
(22%)
high
(43%)
very high
(21%)
all CHF
(100%)
3.6 Chronic conditions, co-morbidity and
use of health care services
Individuals with chronic conditions were more
likely to use more services than those with acute
conditions. As shown in Table 4, on average,
individuals with chronic conditions used 4 times
the inpatient hospital days, and twice the physician
visits of those with acute conditions (age/sexstandardized rates). As well, individuals with
chronic conditions used almost 4 times as many
direct care visits for home nursing care and home
rehabilitation services, and twice as many home
support hours as those with only acute conditions.
Among seniors, those with chronic conditions used,
on average, more than 3 times the PharmaCare
beneﬁts of those with acute conditions.
Chronic conditions and co-morbidity among residents of British Columbia
| 19
20 |
Centre for Health Services and Policy Research
140
852
ALC days
Total IP days
1903
7701
352564
Specialist visits
Total visits
MSP $
608854
Pharmacare $
35
277
Home rehab visits
Total DC visits
2406
62354
Home support hours
Home support paid
Home Support
242
Home nursing visits
Direct Care
4257
Pharmacare scripts
PharmaCare Plan A & B
5798
GP visits
Medical Services Plan
711
A/R days
Hospital Inpatient Services
Total adults
36341
1409
105
14
79
212460
2257
244509
5640
1094
4512
318
53
255
Acute only
77336
2974
399
47
348
782022
5183
530651
11492
2996
8479
1322
187
1136
Conﬁrmed
chronic
75438
2900
417
48
366
827782
5412
554094
11900
3049
8838
1399
185
1221
HI/HP CC
Table 4: Standardized (age/sex) utilization rates per 1000 population by patient category, 2000/01
39094
1508
158
11
144
499136
2842
139607
3709
665
3072
150
14
137
HI/HP CC
No CM
45651
1750
164
18
145
624177
3827
252295
6459
1258
5240
185
18
168
HI/HP CC
Low CM
58635
2269
258
33
224
760459
5001
459140
10721
2459
8285
603
71
536
HI/HP CC
Med CM
88964
3414
532
64
466
973489
6527
765145
15940
4326
11550
1852
239
1638
HI/HP CC
High CM
169173
6457
1335
142
1193
1310436
8791
1518141
28367
8772
19287
6308
761
5689
HI/HP CC
High CM
While there were utilization differences between
those with acute conditions and those with
chronic conditions, it is also important to
recognize the role of co-morbidity in service
utilization. Individuals with HI/HP CCs and no
co-morbidity used fewer physician and hospital
services than those with acute conditions, after
adjusting for age and sex. Similarly, individuals
with HI/HP CCs and low co-morbidity were
relatively low users of health care services. For
example, individuals with HI/HP CCs and low
co-morbidity used 185 inpatient days/1000
population compared with 318 days/1000
population for those with acute conditions and
852 days/1000 population for the total study
population (age/sex-standardized).
Similar patterns were found across geographic
areas in British Columbia. Individuals with HI/
HP CCs and very high co-morbidity used 3.5
to 4.5 times more physician visits and 6.5 to 10
times more hospital days than the population
average, after adjusting for age and sex differences.
They also used 4 to 8 times the direct care (home
nursing and home rehabilitation) and 2 to 4 times
the home support services as the population
average, and 2 to 2.5 times the PharmaCare costs
of seniors in general (Appendix B).
We found a consistent trend to increased
utilization with increasing co-morbidity, with
service utilization rates increasing substantially
among individuals with high or very high comorbidity. Hospital inpatient utilization, including
alternate level of care hospital days, was notably
higher for individuals with HI/HP CCs and high
or very high co-morbidity. Similar patterns were
observed for physician, home nursing care, home
rehabilitation, and home support services, as well
as seniors’ use of PharmaCare services. Those
with HI/HP CCs and very high co-morbidity used
7 times the inpatient hospital days, almost 4 times
the medical visits, almost 5 times the direct care
visits, and 2.5 times the home support hours of
the population average, after adjusting for age
and sex.
This suggests that the combination of conditions
and overall morbidity experienced by individuals
is an important determinant of health services
utilization.
Chronic conditions and co-morbidity among residents of British Columbia
| 21
3.7 Chronic conditions, co-morbidity and
high users of health care services
In light of these ﬁndings, further analysis was
undertaken to compare those with chronic
conditions and co-morbidity to high users of
health care services. High users—the top 5 per
cent of physician services users—have been shown
to use 17 per cent of visits to general practitioners,
30 per cent of specialist visits, 36 per cent of
hospitalizations, and 63 per cent of hospital days
in British Columbia during 1996/97.14 Applying
a similar deﬁnition of high users to this 2000/01
study population identiﬁed 146,666 adults as high
users (Table 5).
Only 1 per cent of those with acute conditions
were high users of services. By comparison, 11.6
per cent of those with chronic conditions were
high users of health services. The proportion
of individuals who were high users increased
steadily as co-morbidity increased, from 1 to 2
per cent of those with HI/HP CCs and no or
low co-morbidity, to 65 per cent of those with
HI/HP CCs and very high co-morbidity. Clearly,
co-morbidity is an important factor inﬂuencing
utilization of health care services.
Table 5: High users by patient category, 2000/01
High users
(n=146,666)
n
Not high users
(n=2,786,639 )
TOTAL
% distribution
Total adults 18+
2,933,305
5.0
95.0
100.0
Acute conditions
954,803
1.3
98.7
100.0
1,046,954
11.6
88.4
100.0
HI/HP CC*
815,648
12.8
87.2
100.0
HI/HP CC No CM
73,041
0.8
99.2
100.0
HI/HP CC Low CM
227,221
1.6
98.4
100.0
HI/HP CC Med. CM
250,183
6.4
93.6
100.0
HI/HP CC High CM
210,826
23.2
76.8
100.0
HI/HP CC V. High CM
54,377
65.1
34.9
100.0
Chronic conditions
*Excludes those with HI/HP CCs and pregnancy ACGs due to signiﬁcant short-term resource impact associated
with pregnancy. See Table 3.
22 |
Centre for Health Services and Policy Research
4. Discussion
In 2000/01, a signiﬁcant portion of the adult
population of British Columbia—at least 36 per
cent—had one or more chronic conditions and
a further 18 per cent had one or more possible
chronic conditions. Both prevalence and impact
of chronic conditions are important factors in
planning health services to meet population
needs. Some chronic health conditions—recurrent
depression, hypertension—had very high treatment
prevalence rates affecting a signiﬁcant proportion
of the population. Other conditions— congestive
heart failure, cerebrovascular disease—were lower
prevalence but had very high impact and use of
health services. Moreover, the highest prevalence
conditions were relatively lower impact, while
many of the lower prevalence conditions were
higher impact. Focusing only on prevalence
risks overlooking chronic conditions that have a
very high impact for a smaller proportion of the
population but are, nonetheless, important to
overall utilization. The combination of prevalence
and impact must be recognized in planning and
allocating limited health care resources.
Prevalence and expected resource use also varied
according to the speciﬁc chronic condition and
associated co-morbidity. Two-thirds of diabetes
patients had no, low, or medium co-morbidity and
were not expected to consume signiﬁcantly more
resources than the population average. However,
one-third of those with diabetes had high or very
high co-morbidity, with those in the very high
co-morbidity category expected to use almost 12
times the resources of the population average.
Among those with congestive heart failure, 64 per
cent had high or very high co-morbidity and were
expected to use 6 and 14 times the population
average, respectively. Similar results were found
for each high impact/high prevalence chronic
condition in this study, although the distribution
of individuals with high and very high comorbidity and impact varied from a relatively
lower proportion for depression, hypertension,
and diabetes to higher for those with congestive
heart failure and cerebrovascular disease.
Therefore, in addition to prevalence and impact
of speciﬁc chronic conditions, it is important
to recognize co-morbidity when planning
and delivering chronic care services. For the
overall adult population, 11 per cent had high
co-morbidity and 2 per cent had very high comorbidity. Among those with acute conditions,
2.5 per cent had high or very high co-morbidity
and 1 per cent were identiﬁed as high users of
services. However, 30 per cent of adults with
chronic conditions had high or very high comorbidity. Both expected and actual health
services utilization increased as co-morbidity
levels increased and those with HI/HP CCs and
very high co-morbidity were more likely to be high
users of health care services. Focusing on speciﬁc
chronic conditions fails to fully describe the need
for and use of services by individuals.
The ﬁnding that health services utilization
rates increased as co-morbidity increased was
consistent with a number of other studies. Wolff
et al. reported signiﬁcantly higher utilization rates
for American Medicare beneﬁciaries with chronic
conditions and co-morbidity, as well as increased
likelihood of ambulatory care sensitive condition
hospitalizations.15 Reid et al. found that high users
were likely to have multiple conditions14 and Roos
et al. reported that presence of three or more coexisting conditions was signiﬁcantly predictive of
physician visits by hypertension patients.38
Programs focusing on a speciﬁc disease fail to
address the range of chronic conditions, overall
morbidity, and broader needs of individuals with
multiple chronic conditions.25,39 These diseasespeciﬁc programs do not recognize the complexity
of 30 per cent of the chronic condition population
who have high or very high co-morbidity and who
Chronic conditions and co-morbidity among residents of British Columbia
| 23
are likely to have high utilization of services. In
order to fully recognize the health service needs of
individuals with chronic conditions, it is essential
to understand the full range of conditions
experienced and to provide services appropriate to
those needs.
Focusing on a speciﬁc chronic condition also fails
to recognize the amenability of individuals to
speciﬁc interventions. Individuals with a chronic
condition and low co-morbidity may be amenable
to programs offering regular monitoring,
preventive care, and self-management education,
while those with chronic conditions and medium
co-morbidity may require more active follow-up
to augment monitoring and self-management
and to coordinate services and care for multiple
conditions. However, the 30 per cent of adults
with chronic conditions and high or very high
co-morbidity will have very different needs,
which may include active case management and
coordinated care for the spectrum of conditions
which they experience. The importance of
co-morbidity contributes to “the futility of
reductionistically carving up patients on the
basis of individual conditions and sending
them to the diabetes program on Monday, the
cardiac program on Tuesday, the arthritis
program on Wednesday, and the depression
program on Thursday. What is needed is a model
of care that addresses the whole person and
integrates care for the person’s entire constellation
of co-morbidities.”39
While many components of chronic care
may be similar for individuals with multiple
chronic conditions (e.g. use of evidence-based
guidelines, clinical information systems, and
multi-disciplinary care), there will be additional
needs for coordination and active management
of care. As an example, some chronic disease
programs focus on drug therapies to manage
24 |
Centre for Health Services and Policy Research
speciﬁc conditions. The risk of drug interactions
and conﬂicting care advice is compounded as comorbidity increases. Beneﬁts associated with care
management may also vary. A recent evaluation
of nurse care management for low risk congestive
heart failure patients found no beneﬁt to rehospitalization rates with care management and
found that most emergency department visits and
re-hospitalizations were for co-morbid conditions.40
Not only are the care needs of individuals with
co-morbidity more complex, but the ability of
individuals with chronic disease co-morbidity
to undertake self-management of their range
of conditions is different. Those with multiple
chronic conditions or co-morbidity may be
less likely to beneﬁt from self-management.41
Barriers to self-management may include physical
limitations, aggravation of one condition by
symptoms or treatment for other conditions,
medication interactions, and conﬂicting care
recommendations, along with “overwhelming
effects” of speciﬁc conditions. Some high impact
conditions such as congestive heart failure or
cerebrovascular disease may inhibit use of selfmanagement techniques or compliance with other
disease management recommendations, such as
diet and exercise.
Case management or care management has been
proposed for managing the needs of complex
patients with multiple chronic conditions. Care
management programs typically use multi-faceted
approaches, including education, clinical, and
community/social services to provide care to
individual patients with high needs.42 The utility of
stratifying patients by co-morbidity and risk has
been supported with the development of predictive
modeling tools to prospectively identify patients
at high risk and is used by providers for targeted,
intensive management in the US.43,44 Some primary
care trusts have also undertaken case management
in the UK, often using nurse providers working
closely with patients and providers as well as
recognizing the interplay of social factors in
addition to complex clinical needs.45
The presence of co-morbidity for many
individuals with chronic conditions has also
led to recommendations for an increased role
for primary health care and speciﬁcally for care
that combines the unique attributes of primary
care with important components of chronic
care management: ﬁrst contact, comprehensive,
coordinated, and longitudinal care.24 Each of the
unique attributes of primary care is important
to the management of care for individuals with
multiple chronic conditions. First contact care
provides an entry point to health care services
and referrals to specialty care as required.
Comprehensive care addresses the needs for
health promotion, prevention, diagnosis,
treatment, rehabilitation, and palliative care,
depending on the patient’s constellation of needs.
Longitudinal care recognizes the need for ongoing
care and understanding the patient’s context.
Continuity reﬂects the importance of relational,
informational, and management continuity for
individual complex needs, and coordination
recognizes the need for a coordinating role across
the range of services.16 Indeed, some primary
care providers in the UK have developed links
with social services to meet patient needs.45
Primary care may be uniquely suited to meet
the combination of clinical, behavioural,
psychosocial, and socioeconomic needs of those
with multiple chronic conditions and complex
care needs.46
Further work is required to analyze the actual
experience of British Columbia residents with
chronic conditions and co-morbidity, their use of
primary care services, and their continuity of care.
Chronic conditions and co-morbidity among residents of British Columbia
| 25
5. Conclusions
In summary:
What is the experience of British Columbians
with chronic disease and co-morbidity? At least
36 per cent of adults and 68 per cent of seniors
had at least one conﬁrmed chronic condition
and a further 18 per cent of adults and 15 per
cent of seniors had possible chronic conditions.
The majority of adults with chronic conditions
experienced co-morbidity and 30 per cent of
adults with chronic conditions had high or very
high co-morbidity.
How do individuals with chronic disease and comorbidity use health care services compared to
individuals with no chronic conditions or individuals
with chronic conditions and no or low co-morbidity?
On average, those with chronic conditions had
higher standardized utilization rates across all
health care services (acute, medical, direct home
care, home support, and seniors’ PharmaCare)
compared to those with acute conditions.
However, after stratifying by co-morbidity level,
it is apparent that those with chronic conditions
and no or low co-morbidity had relatively low
utilization rates, while those with high and very
high co-morbidity had notably higher use of
health care services. Standardized utilization
rates increased consistently with increasing comorbidity. Similar patterns were evident across
health authorities.
How do individuals with chronic disease and comorbidity overlap with high users of health care
services? Do chronic disease programs target those
with highest use of services? Adults with chronic
condition(s) were more likely to be high users
of health care services than those with acute
conditions only. Those with chronic condition(s)
and high or very high co-morbidity were much
more likely to be high users of health care services
than those with chronic conditions and no or low
co-morbidity. This research suggests that disease26 |
Centre for Health Services and Policy Research
speciﬁc programs targeting individual conditions
do not recognize the importance of co-morbidity
in health services utilization and the role of comorbidity in driving utilization of health care
services. High users of services were signiﬁcantly
more likely to have high or very high levels of comorbidity and to experience multiple types
of conditions.
6. Limitations
Data for this study were drawn from
administrative data ﬁles and were subject to
limitations resulting from missing Alberta
utilization and Alternative Payments Program
(APP) data. This constraint will likely result in
an under-estimate of chronic conditions, comorbidity, overall morbidity, and utilization in
those areas with signiﬁcant utilization of Alberta
and APP services.
Impact and expected resource use estimates were
based on hospital and medical costs. Actual
utilization rates incorporate home care, home
support, and pharmaceutical use by seniors.
Information was not available to assess
functional status, quality of life, or long-term
outcomes for individuals with chronic conditions
and co-morbidity.
Chronic conditions and co-morbidity among residents of British Columbia
| 27
Appendix A:
Distribution of study population by patient category
Table A.1 Distribution by patient category, health service delivery area and health authority
Total
adults 18+
Non-users
Acute only
n
Possible
chronic
conditions
Conﬁrmed
chronic
conditions
TOTAL
HI/HP CCs
% of
conﬁrmed
chronic
% of total
Health Service Delivery Areas
Fraser East
164,883
11.2
33.0
18.1
37.7
100.0
80.6%
Fraser North
376,960
13.2
33.9
18.6
34.3
100.0
77.5%
Fraser South
407,954
11.3
31.3
19.5
37.9
100.0
79.1%
Richmond
126,983
15.9
33.2
18.5
32.4
100.0
77.2%
Vancouver
443,767
15.4
31.9
18.3
34.4
100.0
76.3%
North Shore/Coast Garibaldi
194,305
12.8
36.4
19.0
31.8
100.0
79.3%
South Vancouver Island
251,129
10.7
32.5
18.2
38.6
100.0
81.0%
Central Vancouver Island
174,130
11.3
30.7
17.7
40.3
100.0
80.3%
North Vancouver Island
81,218
12.3
30.5
19.4
37.8
100.0
79.3%
East Kootenay
55,867
16.0
37.4
16.8
29.8
100.0
81.8%
Kootenay Boundary
59,543
14.8
33.6
17.4
34.2
100.0
81.2%
Okanagan
226,426
11.2
30.8
18.2
39.8
100.0
83.8%
Thompson Cariboo Shuswap
154,756
13.9
31.9
18.4
35.8
100.0
80.9%
North West
58,838
20.3
30.8
18.6
30.3
100.0
81.5%
Northern Interior
105,089
16.5
33.8
17.9
31.8
100.0
77.4%
North East
41,473
18.8
35.2
18.1
27.9
100.0
79.9%
Fraser
949,797
12.1
32.6
18.9
36.4
100.0
78.8%
Vancouver Coastal
765,055
14.8
33.3
18.5
33.4
100.0
77.2%
Vancouver Island
506,477
11.2
31.6
18.2
39.0
100.0
80.5%
Interior
496,592
13.0
32.2
18.0
36.8
100.0
82.4%
Northern
205,400
18.0
33.3
18.1
30.6
100.0
79.0%
2,933,305
13.3%
32.6%
18.5%
35.7%
100.0%
79.4%
Health Authorities
British Columbia
Note: 9984 IDs had missing geographic information and could not be assigned to HSDAs or HAs.
28 |
Centre for Health Services and Policy Research
Table A.2 Age/sex-standardized distribution by patient category and health authority
Non-users
Acute only
Possible
chronic
conditions
Conﬁrmed
chronic
conditions
TOTAL
HI/HP CCs
% of conﬁrmed
chronic
% of total
Health Authorities
Fraser
11.9%
31.9%
18.8%
37.4%
100.0%
79.1%
Vancouver Coastal
14.6%
32.8%
18.5%
34.1%
100.0%
77.5%
Vancouver Island
11.8%
33.3%
18.4%
36.6%
100.0%
81.1%
Interior
13.5%
33.8%
18.1%
34.6%
100.0%
81.9%
Northern
16.9%
30.6%
17.9%
34.5%
100.0%
80.5%
British Columbia
13.3%
32.6%
18.5%
35.7%
100.0%
79.4%
Chronic conditions and co-morbidity among residents of British Columbia
| 29
Appendix B:
Standardized utilization rates of health care services
Table B.1 Hospital utilization rates
TO T A L H O S P I T A L D A Y S / 1 0 0 0
Total adults
18+
POPULATION
(AGE/SEX
STANDARDIZED)
Acute only
Chronic EDCs
HI/HP CCs
HI/HP CC with
V. High CM
Health Service Delivery Areas
Fraser East
813
363
1,184
1,256
5,784
Fraser North
837
273
1,335
1,431
6,643
Fraser South
841
273
1,266
1,329
5,507
Richmond
721
221
1,240
1,353
6,447
Vancouver
833
276
1,337
1,396
6,527
North Shore/Coast Garibaldi
787
263
1,319
1,422
5,972
South Vancouver Island
838
293
1,223
1,276
5,875
Central Vancouver Island
879
313
1,265
1,350
5,905
North Vancouver Island
988
324
1,520
1,570
6,698
East Kootenay
944
520
1,472
1,509
7,229
1,029
471
1,575
1,518
6,641
Okanagan
744
246
1,107
1,171
5,628
Thompson Cariboo Shuswap
976
391
1,517
1,618
8,059
North West
1,305
1,071
2,165
2,135
9,991
Northern Interior
1,112
435
1,904
1,931
9,155
North East
1,210
607
2,136
2,152
11,775
Fraser
834
290
1,275
1,351
5,950
Vancouver Coastal
804
263
1,318
1,396
6,380
Vancouver Island
872
303
1,276
1,338
6,002
Interior
861
349
1,299
1,354
6,472
1,186
647
2,019
2,028
9,776
852
318
1,322
1,399
6,308
Kootenay Boundary
Health Authorities
Northern
British Columbia
30 |
Centre for Health Services and Policy Research
Table B.2 Medical services utilization rates
TO T A L M S P V I S I T S / 1 0 0 0
Total adults
18+
POPULATION
(AGE/SEX
STANDARDIZED)
Acute only
Chronic EDCs
HI/HP CCs
HI/HP CC with
V. High CM
Health Service Delivery Areas
Fraser East
8,190
6,062
11,532
11,842
29,330
Fraser North
7,854
5,862
11,771
12,225
28,758
Fraser South
8,354
5,985
12,019
12,331
28,633
Richmond
7,158
5,417
11,310
11,740
28,304
Vancouver
7,705
5,683
11,875
12,345
27,987
North Shore/Coast Garibaldi
7,423
5,487
11,449
11,896
28,913
South Vancouver Island
8,063
5,609
11,524
11,874
27,437
Central Vancouver Island
7,948
5,518
11,220
11,661
28,021
North Vancouver Island
7,678
5,423
11,277
11,747
28,733
East Kootenay
7,276
6,002
11,151
11,384
26,863
Kootenay Boundary
6,925
5,180
10,623
10,996
28,680
Okanagan
7,671
5,301
10,970
11,353
28,054
Thompson Cariboo Shuswap
7,072
5,286
10,571
10,962
27,790
North West
6,739
5,201
11,533
11,910
29,919
Northern Interior
7,058
5,358
11,354
11,614
29,477
North East
6,374
5,418
10,423
10,568
29,090
Fraser
8,129
5,948
11,837
12,200
28,796
Vancouver Coastal
7,542
5,584
11,680
12,136
28,258
Vancouver Island
7,965
5,551
11,380
11,780
27,851
Interior
7,360
5,373
10,831
11,205
27,952
Northern
6,830
5,329
11,233
11,506
29,558
British Columbia
7,701
5,640
11,492
11,900
28,367
Health Authorities
Chronic conditions and co-morbidity among residents of British Columbia
| 31
Table B.3 Direct care service (home nursing and home rehab) utilization rates
TO T A L D I RE C T C A RE V I S I T S / 1 0 0 0
Total adults
18+
POPULATION
(AGE/SEX
STANDARDIZED)
Acute only
Chronic EDCs
HI/HP CCs
HI/HP CC with
V. High CM
Health Service Delivery Areas
Fraser East
201
75
282
296
856
Fraser North
296
126
419
433
1,417
Fraser South
165
67
226
230
752
Richmond
281
123
419
459
1,280
Vancouver
294
107
424
440
1,369
North Shore/Coast Garibaldi
263
96
406
435
1,412
South Vancouver Island
264
91
364
384
1,154
Central Vancouver Island
303
92
425
463
1,483
North Vancouver Island
308
87
447
471
1,757
East Kootenay
309
98
496
525
2,154
Kootenay Boundary
460
217
649
650
1,748
Okanagan
277
77
398
412
1,425
Thompson Cariboo Shuswap
388
120
579
620
2,122
North West
345
316
524
533
1,738
Northern Interior
359
99
565
582
2,061
North East
580
311
957
1,005
4,521
Fraser
221
92
307
316
1,003
Vancouver Coastal
284
106
419
442
1,367
Vancouver Island
283
91
395
422
1,346
Interior
331
109
482
502
1,689
Northern
399
206
627
647
2,314
British Columbia
277
105
399
417
1,335
Health Authorities
32 |
Centre for Health Services and Policy Research
Table B.4 Home support service utilization rates
TO T A L H O M E S U P P O R T H O U R S / 1 0 0 0
Total adults
18+
POPULATION
(AGE/SEX
STANDARDIZED)
Acute only
Chronic EDCs
HI/HP CCs
HI/HP CC with
V. High CM
Health Service Delivery Areas
Fraser East
2,419
1,331
2,996
3,008
6,424
Fraser North
2,220
1,380
2,664
2,613
5,309
Fraser South
1,949
1,148
2,327
2,261
5,090
Richmond
2,078
943
2,712
2,777
6,100
Vancouver
2,964
1,680
3,669
3,510
7,547
North Shore/Coast Garibaldi
2,173
1,137
2,641
2,663
5,928
South Vancouver Island
2,551
1,574
2,903
2,806
5,813
Central Vancouver Island
2,528
1,312
3,043
3,069
7,111
North Vancouver Island
3,459
2,227
4,284
4,375
11,828
East Kootenay
3,087
1,246
4,228
4,117
11,614
Kootenay Boundary
3,213
2,694
3,755
3,622
7,162
Okanagan
2,082
1,428
2,509
2,433
5,950
Thompson Cariboo Shuswap
2,226
877
2,921
2,968
6,741
North West
2,106
1,229
2,918
2,787
6,583
Northern Interior
2,756
1,122
3,894
3,775
9,132
North East
3,654
2,989
4,725
4,359
9,162
Fraser
2,144
1,279
2,583
2,538
5,376
Vancouver Coastal
2,623
1,395
3,278
3,194
6,963
Vancouver Island
2,647
1,562
3,108
3,069
6,993
Interior
2,353
1,451
2,905
2,842
6,687
Northern
2,752
1,558
3,795
3,622
8,401
British Columbia
2,406
1,409
2,974
2,900
6,457
Health Authorities
Chronic conditions and co-morbidity among residents of British Columbia
| 33
Table B.5 PharmaCare for seniors’ service utilization rates
TO T A L P H A R M A C A RE $ PA I D / 1 0 0 0
Total adults
18+
POPULATION
(AGE/SEX
STANDARDIZED)
Acute only
Chronic EDCs
HI/HP CCs
HI/HP CC with
V. High CM
Health Service Delivery Areas
Fraser East
696,183
248,696
875,747
931,420
1,395,822
Fraser North
616,108
211,645
778,310
828,539
1,302,612
Fraser South
641,856
183,769
797,079
845,375
1,274,903
Richmond
581,148
183,066
771,952
813,651
1,316,502
Vancouver
569,351
197,106
730,710
779,224
1,217,924
North Shore/Coast Garibaldi
564,078
235,670
744,895
791,012
1,274,167
South Vancouver Island
634,915
254,924
788,463
836,566
1,293,308
Central Vancouver Island
627,126
179,295
785,112
840,509
1,354,254
North Vancouver Island
636,310
145,893
802,800
864,563
1,424,088
East Kootenay
581,910
287,908
780,243
825,566
1,481,149
Kootenay Boundary
577,154
202,444
762,781
815,068
1,244,951
Okanagan
634,512
231,116
810,295
857,850
1,405,874
Thompson Cariboo Shuswap
585,788
166,879
763,753
814,447
1,307,155
North West
507,330
135,819
714,974
763,318
1,244,195
Northern Interior
606,725
156,561
789,472
850,006
1,408,889
North East
539,439
173,488
753,700
814,885
1,451,851
Fraser
643,883
210,442
806,469
857,074
1,304,659
Vancouver Coastal
569,681
208,563
740,607
787,586
1,246,394
Vancouver Island
632,321
220,674
789,039
841,488
1,333,374
Interior
610,713
221,259
790,525
839,369
1,369,309
Northern
565,554
153,790
763,005
820,293
1,367,615
British Columbia
608,854
212,460
782,022
827,782
1,310,436
Health Authorities
34 |
Centre for Health Services and Policy Research
Appendix C: Data methods
Use of ICD9 diagnosis codes to determine
morbidity has been tested and validated both
in Canada and in other jurisdictions.47 Previous
analyses comparing treatment prevalence data for
Vancouver Coastal residents with self-reported
chronic conditions from National Population
Health Survey data indicated high speciﬁcity
and relatively high sensitivity which was further
increased by introducing the requirement for
two or more medical diagnoses.48 As well, good
face validity has been reported for selected
conditions in previous analyses. However, it is
important to recognize that some conditions may
be less likely to be identiﬁed using administrative
data, particularly for individuals with multiple
conditions requiring medical attention. MSP
diagnosis information is limited to a single
diagnosis per visit, leading to the possibility that
secondary diagnoses and lower impact chronic
conditions treated mainly with ambulatory care
may be under-reported in administrative data ﬁles.
Geographic home location was based on the
resident’s longest home location during the study
year. Individuals who moved during the year were
assigned to a single home local health area (LHA)
based on length of residence.
Utilization data for acute care services accessed
by British Columbia residents in Alberta hospitals
were not included in the BC Linked Health
Database and were not available for this study.
Missing Alberta data potentially understate
chronic condition prevalence and co-morbidity
estimates for residents in areas using hospital
services in Alberta: i.e. LHAs adjacent to the
Alberta border, including Fernie, Cranbrook,
Windermere, Golden, North Thompson, Peace
River South, and Peace River North. Morbidity
in rural and remote areas may also be understated
if residents of these areas have relatively less
access to health care services since identiﬁcation
of speciﬁc chronic conditions was dependent upon
receipt of services and recording of diagnoses.
Reduced access to medical and hospital services
may result in reduced identiﬁcation of both
speciﬁc chronic conditions and overall morbidity
for residents of rural and remote areas.
Utilization rates for individuals with acute,
chronic and HI/HP CC conditions were derived
using administrative data for each program.
Hospital days included all days incurred by
individuals with one or more separations during
the ﬁscal year. Acute/rehab days and alternate
level of care days were based on hospital
discharge abstract data. MSP visits included all
visits during the study year for fee payments >
$0, excluding laboratory and diagnostic services.
Visits were aggregated to a maximum of one visit
per patient and provider per day to adjust for
multiple billings for the same patient/physician/
date combination. Physician specialty was based
on type of practice. Direct care services were
based on Continuing Care IMS system records
for home nursing care and home rehab (PT/OT)
visits while home support utilization was based on
home support service hours. Utilization rates were
calculated based on all individuals in the category,
irrespective of whether they actually used services,
and were age/sex standardized to adjust for the
impact of increasing age and gender on utilization
of health care services.
Chronic conditions and co-morbidity among residents of British Columbia
| 35
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| 39
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